Clothes drier structure and control



. Jan. 31, 1967 v R. P. BERGESON ETAL CLOTHES DRIER STRUCTURE ANDCONTROL Filed Feb. 28, 1964 2 Sheets-Sheet 1 /40 ii i? 1 2.

a o o 0 /22 RICHARD P Bsxeasso/v GUA QA/v D. Corrorv m57 Z gf 4.

AGENT 1957 R. P. BERGESON ETAL 3,300,369

CLOTHES DRIER STRUCTURE AND CONTROL Filed Feb. 28, 1964 2 Sheets-Sheet 2FFiQiZ U m Y.

Ham/7' United States Patent C) 3,390,869 CLOTHES DR STRUCTURE ANDCGNTROL Richard P. Bergeson and Curran D. Cotton, Newton, Iowa,assignors to The Maytag Company, Newton, Iowa, a corporation of DelawareFiled Feb. 28, 1964, Ser. No. 348,051 3 Claims. (Cl. 3445) Thisinvention relates to devices employed in a control system for directlydetermining the condition of fabrics in a machine for drying fabrics,and more particularly, to electrodes for contacting and completing anelectrical circuit through the fabrics.

Many attempts have been made to relate and control the termination pointof drying operations to the condition of the fabrics. One system reliesupon the change in conductivity of the fabrics as the moisture isremove-d to discontinue operation of a drying machine at the momentelectrical conductivity of the fabrics, as sensed directly betweenconductors mounted on and movable with the revoluble drum, attains apredetermined value.

Another system is disclosed in the pending application of Thomas R,Smith, Serial No. 329,155, filed December 9, 1963, and assigned to theassignee of the instant invention. Said application concerns a drycontrol system in which the electrical conductivity of the randomtumbled fabrics, integrated over a period of time, attains apredetermined value before initiating termination. Electricalconductivity is sensed directly between conductors mounted on the innerperiphery of the revoluble drum.

In both of these systems, it is noted that the conductors are mounted onthe revoluble drum and movable therewith. Thus of necessity, means mustbe provided for carrying current from the revoluble drum to a stationarymember. One such current carrying system is a slip ring and brusharrangement, for example. It is known that the use of moving parts forcarrying current may result in increased manufacturing and operatingproblems. It is also known, of course, that as additional parts are in--cluded in the control system as required with a slip ring and brusharrangement, additional cost is correspondingly added.

Additional problems are encountered when a combination washer-drier isprovided with an automatic control system requiring that electrodes bepositioned within the washing and drying chamber. The problem of havingelectrodes in the revoluble drum and of connecting them to the controloutside a casing or tub is made more critical because of the presence oflint-laden wash water. First, the use of connecting wires createmounting and sealing problems, Second, the collection of lint from thewash water on the electrodes and on the connecting wires is troublesomeand may result in erratic operation of the control system.

It is therefore an object of this invention to provide for a dry controlsystem improved electrodes positioned for contact by the fabrics beingtumbled.

It is a further object of this invention to provide in proved means formounting the electrodes for contact by the fabrics being tumbled.

It is a further object of this invention to provide electrode meanspositioned for contact by the tumbled fabrics and mounted on anon-revoluble member thereby eliminating the need for relatively movablecurrent carrying members.

It is still a further object of this invention to provide electrodemeans which are more suitable for use in a washer-drier unit by reasonof the elimination of any lint collection during the washing operation.

These objects are realized in the present invention by the provision ofelectrodes positioned on a non-revoluble member juxtaposed to therevoluble drum and openly facing the interior thereof. Specifically, inthe preferred embodiment, the electrodes are positioned in a washerdrieron a non-revoluble member which openly faces the drum interior betweenthe inner periphery of an opening provided in the front wall member ofthe revoluble drum and the access opening provided in the machineenclosure.

Oomplete details of this invention and further objects and advantageswill become evident as the description proceeds and from an examinationof the accompanying drawings which illustrate a preferred embodiment ofthe invention and in which similar numerals refer to similar partsthroughout the several views.

In the drawings:

FIGURE 1 is a side view of a washer-drier shown partially in section andincluding the subject matter of the instant invention;

FIGURE 2 is a sectional view taken along line 2-2 of FIGURE 1 showingthe interior of the tub front and more particularly showing the subjectmatter of the instant invention;

FIGURE 3 is shown below FIGURE 1 and is a schematic electrical circuitshowing a control system cooperable with the present invention; and

FIGURE 4 is a fragmentary sectional view of a drier showing anadditional embodiment of the present invention.

Referring now to the accompanying drawings in detail, it will be seenthat a combination washer-drier unit, shown in FIGURES 1 and 2, andadapted to include a preferred embodiment of the present invention, isdescribed hereinafter. For a complete explanation of the structuraldetails of a washer-drier of this type, however, attention is directedto US. Patent 2,985,966, issued May 30, 1961, to Paul A. Martin andassigned to the same assignee as the instant invention, It is to benoted also that the instant invention is applicable for use with afabric treating apparatus intended solely for drying fabrics, as will bediscussed more fully in explaining the embodiments shown in FIGURE 4.

The washer-drier shown in FIGURES 1 and 2 includes a substantially flatsurfaced base frame 10 supported on legs 11. Mounted upon base frame 10are channel members 13 and 14 which are welded or otherwise securelyatlixed in some suitable manner to base frame 10 to form the two majorsupports for the washer-drier unit of FIG- URE 1.

As seen in FIGURE 1, channel members 13 and 14 receive pivot pins 16 and17 to form a two-point support for tub 20 on tub brackets 23 and 24respectively. This allows tub or casing 20, which is fastened to tubbrackets 23 and 24, to oscillate or pivot back and forth in a primarydegree of freedom on pins 16 and 17 in response to various forcesgenerated within tub 20.

Tub 20 is maintained in an upright position on pins 16 and 17 by twocentering springs such as spring 25 connected between tub 20 and base10. FIGURE 1 also shows tub 20 as being provided with a damperarrangement including damper leaf spring 30 fixed to tub 20 and carryingthe damper pad 33 engageable with upstanding damper plate 34 forabsorbing and dissipating the energy imparted to tub 20 by centrifugalforces generated during extraction operations involving unbalancedloads. An unbalanced control system, such as may include an actuatingplunger 32, may be employed to prevent excessive vibrations.

It is seen that this assembly supported on pins 16 and 17, including tubor casing 20, is enclosed within a cabinet 35. Cabinet 35 is providedwith an access door 36 hinged to cabinet 35. Door 36 may be manuallyopened for allowing frabics to be inserted through opening 37 into 3clothes receptacle or drum 38 positioned within tub or casing 20.

Tub includes a generally cylindrical side wall 71, a pair of spaced rearwalls 72 and 73 and a front wall 74. Front wall 74 terminates in aninner flange portion 77 encircling loading opening 78. Flange portion 77may be substantially vertical as shown in FIGURE 1 or be slanted to faceinwardly and upwardly for contact by the fabrics. The front and outerwalls 74 and 72, respectively, are connected to cylindrical side wall 71by means of the encompassing flanged hoop-like members 76 while thepartition wall 73 positioned between walls 72 and 74 is welded to sidewall '71.

It will be seen from an inspection of FIGURE 1 that the spaced rearwalls 72 and 73 support the tub bearing assembly generally indicated bythe reference number 80. The tub bearing assembly 88 includes a spacerhub 81 which is located between and which abuts the rear walls 72 and73, and a tubular clamp member (not shown) located concentrically withinhub 81. The clamp member is'formed with a shoulder 85 and a threadedportion 84 for receiving spanner clamp nut 83 which, when tightened onthe tubular clamp member, produces a rigid support with respect to tub20 for two bearing (not shown), one of which is located adjacent each ofwalls 72 and 73 for support of drum drive shaft 89.

The rear end of drum drive shaft 89 is rigidly connected to the largedrive pulley 91 whereas its front end is threaded into hub 94 of drum38. Drum 38 includes a perforate rear wall 96 which is rigidly aflixedto and cooperates with the spider-like brace member 97 to form a doublecone support connected to hub 94 for providing rigid support for thedrum 38 on drum drive shaft 89. The inwardly extending conical rear wallassists in moving the fabrics about in drum 38 and especially aids inmoving the fabrics away from the rear of drum 38. Drum 38 also includesa perforate cylindrical side wall 104 which merges into a short frontwall 106 and which carries elevating means 105.

The circular loading opening 78 is encircled by one end of bellows seal118. The opposite end of seal 118 is fastened to access opening 37formed in cabinet enclosing the combination washer-drier unit.Rectangular door 36 carries a transparent glass window 122 having acylindrical portion 123 extending rearwardly through the bellows seal118 which is provided with a flexible annular sealing lip 124 engageablewith the periphery of the cylindrical portion 123. The unit is thussealed while still onabling the operator of the machine to observeoperations taking place within tub 20 during the washing and dryingprocess. A lamp 126 is fastened to the exterior of tub 20 and shinesthrough a transparent member 127 carried in front wall 74 of tub 20 forilluminating the interior of the machine.

Tub 20 also includes a heater housing 131 which may be formed separatelyor as a part of the casing side wall and which supports a heatingelement (not shown) capable of radiating heat energy through an openinglocated in the cylindrical side wall 71 and covered by the heaterhousing 131. Heater housing 131 also mounts the high limit thermostat133 which is connected in series with the heater. Additionalthermostats, such as 135 and 136, may be placed within or juxtaposed todrum 38 for contact by the tumbled fabrics to prevent excessivetemperature rise in the fabrics.

Drum 38 positioned within tub 20 is connected to drive pulley 91 throughshaft member 89. Pulley 91 is driven by a drive system which includes anelectric motor 137 and variable speed means such as transmission 138 andwhich is operable for delivering a plurality of operating speeds. Thesespeeds may include a relatively slow speed for tumbling the fabricswithin drum 38 during the washing and drying operations, an intermediatespeed for distributing the materials contained within drum 38 in asubstantially even loading about the inner periphery thereof prior toextraction, and a relatively high speed'for extract- 4 ing fluids fromthe materials contained within the drum 38.

A combination blower-condenser unit as described in US. Patent 3,040,440issued June 26, 1962, to Mellinger et al., entitled Washer-DrierCondenser System and assigned to the asignee of the instant invention ispositioned in the compartment formed by and between portions of spacedrear walls 72 and 73. This blower-condenser unit is capable of movingair through tub 20 and drum 38 for drying the fabrics, scrubbing lintfrom this air, and condensing out moisture from hot vapors producedwithin tub 20 during the drying operation.

This washer-drier includes a conventional program control timing device(not shown) for sequencing the machine and the various electricallyoperated components thereof through a predetermined series of operationscomprising a washing and/ or drying operation. The timing device may belocated in control housing 140 and be manually advanced by rotating knob142 to initiate operation of the washer-drier.

This washer-drier is also equipped with a dry control device such asdisclosed in the aforementioned Smith application, Serial No. 329,155,for controlling termination of the drying operation and which includes acontrol circuit as shown in FIGURE 3. When adapted to this machine, thecontrol device is mounted within control housing 140 but may also bemounted elsewhere within cabinet 35.

As seen in FIGURES 1 and 2, conductors 144 and 145, which cooperate withthe dry control for sensing the dryness of the tumbled fabrics, arepositioned on flange 77 of non-revoluble front wall 74. These conductivemembers are preferably in the form of thin flat elongated strips appliedto a portion of the surface of flange 77 openly facing the interior ofrevoluble clothes drum 38. The conductors may also be in the form ofwires or other shapes of conductive material. The electrodes may befixed to the surface with rivets, screws or by bonding with adhesives.The spaced-apart conductors are insulated from each other and from theflange 77 in the preferred embodiment by a non-conductive porcelainenamel finish applied to the surface of the flange and any mountingholes therein. The conductors may also, of course, be insulated from theflanges by positioning an insulative member (not shown) between theflange and the conductor. The insulation means may also include anormally insulating material which becomes at least partially conductiveresponsive to the pickup of moisture from the fabrics. An additionalembodiment of the electrodes for use with a washer-drier combination inwhich front wall 74 of casing 20 is finished with a porcelain enamelsurface is a fired-on strip of conductive material. These fired-onconductors become an integral part of the surface and are substantiallyflush thereto, but are fully insulated from each other and thesupporting flange by the porcelain enamel.

Electrodes 144 and 145 are formed and attached to the surface of flange77 in a manner that the surfaces are substantially free of lint-catchingprotrusions. They may be arranged as arcuate strips as shown in FIGURE 2and be connected to the control circuit at terminals 149 and 150 whichare also insulated from flange 77. Additional electrodes, such asconductors 154 and 155, may be connected electrically parallel toelectrodes 144 and 145 through terminals 149 and 150 and jumper wires(not shown) extending from terminals and 161, respectively.

It is noted that these electrodes comprise a pair of conductors or aplurality of pairs of conductors for contacting the tumbled fabrics;however, it is within the scope of this invention to provide oneconductor insulated from flange member 77 and provide a conductiveportion, a conductive surface, or other means for adapting flange 77 asthe second electrode.

It is further noted in FIGURE 2 that electrodes 144 and 145 arepositioned in substantially the lower right quadrant of circular fiange77 for contact by the tumbled fabrics. Rotation of drum 38 in aclockwise direction, as shown by arrow 147 in FIGURE 2, and the weightand momentum of the fabrics being tumbled tend to cause the fabrics tofall from the upper area of the basket toward this lower right quadrantand thus contact the electrodes.

The automatic dry control relies on measuring the electricalconductivity or resistance of the materials being tumbled fordetermining the condition of dryness thereof. Electrodes 144 and 145 aretherefore positioned for contact by the fabrics or materials beingtumbled so that the fabrics may short between the electrodes. Thecontrol system for measuring this change in electrical conductivityincludes the sensing circuit of FIGURE 3 and is supplied withconventional 110 volt 60 cycle alternating current between power lines Land L Electrodes 144 and 145 are connected electrically to the sensingcircuit by lines 164 and 165 respectively. It is noted that the mountingof the conducting electrodes upon flange 77 of the non-revoluble frontwall 74 eliminates the need for relatively movable current-carryingmembers, such as arrangements which include Slip rings and brushes.

It is understood, of course, that the program control timing device forsequencing this washer-drier through the various operations comprising awashing and/ or drying operation is operative for controlling operationof the sensing circuit to a particular portion of the cycle ofoperations and specifically to the drying operation for determining thetermination point.

The sensing circuit of FIGURE 3 includes a half-wave rectifier 166connected on one side to power line L and on the other side to resistor169. Resistor 169 is in turn connected to one side of a capacitor 170which is in turn connected to power line L through resistor 171. It willbe noted that the electrodes 144 and 145 positioned within the drum 38are connected across the capacitor 174) by lines 164 and 165.

A gaseous discharge tube, such as a neon lamp 174, is also connectedacross capacitor 170. Neon lamp 174 normally has an infinite resistance;however, when the charge on the capacitor 170 reaches a predeterminedvalue, the gas is ionized and the circuit is conducted therethrough toproduce a visible discharge.

A light sensitive cell 175 is positioned to detect the discharge of neonlamp 174. One side of the light sensitive cell 175 is connected by line176 to power line L and the other side of the light sensitive cell isconnected to relay coil 179. The other side of relay coil 179 isconnected to power line L through line 180. Normally, when dark, thelight sensitive cell 175 has a very high resistance. However, when itdetects light, its resistance is greatly reduced and completes thecircuit to energize relay coil 179.

Relay coil 179 operates switches 181 and 184. Switch 181 completes aholding circuit in order to maintain relay coil 179 energized aftervisible discharge of neon lamp 174 terminates. Switch 184 energizestimer motor 185 to initiate operation of the program control device forterminating the drying operation.

During operation of the dry control device, the capacitor 170 is slowlycharged through resistors 169 and 171, but it is also discharged throughelectrodes 164 and 165 when the clothes are wet. However, as the clothesare dried, the average rate of discharge through the fabrics diminishesto the point at which the charge on the capacitor reaches an amountwhich will fire the neon tube 174. This operates the relay coil 179through the photoelectric cell 175. Upon energization of relay coil 179,the program control device is initiated for terminating the operation orfor proceeding into an auxiliary operation.

In order to prevent shorting between electrodes 144 and 145 upon contactby metallic objects, such as buttons, clips, and the like, means such asridges 187 or barriers may be placed between the electrodes andprotruding above the surface thereof to prevent simultaneous contact ofthe electrodes by a metallic object. Ridges 187 are non-conductive byreason of a porcelain enamel finish, for example, and prevent shortingbetween the conductors by substantialy rigid conductive objects.

These improved electrode structures offer distinct advantages when usedwith a combination washer-drier.

These stationary structures, in addition to having advantages as aresult of the stationary feature, avoid or prevent the accumulation oflint and other foreign particles between the electrodes which wouldresult in undesirable and inconsistent operation of the dry controlsensing system during the drying operation. In addition, thesubstantially flush configuration of the electrodes upon the fiangemember insures the maintainance of clean electrodes because of theconstant wiping action of the tumbling fabrics.

The improved electrodes and the improved means for mounting thereof may,of course, be used with a conventional drying apparatus in which 'asingle drum or clothes-containing member is used. In FIGURE 4 is shown afragmentary sectional view of a drier adapted to utilize the electrodesof the instant invention. This view is sufiicient to show thepositioning of the electrodes on a non-revoluble member and positionedfor contact by the materials being tumbled; however, a completedisclosure and description of the drying apparatus embodying thisgeneral construction is shown in US. Patent 2,958,138 entitled ClothesDrier With Stationary Cowling issued November 1, 1960, to Alfred T.Ashby and assigned to the assignee of the instant invention. This drierincludes a drum 189 for tumbling the fabrics therein and furtherincludes a short perforate front wall member 190. Juxtaposed to frontwall member 190 and having a flange member 192 openly facing theinterior of drum 189 is the stationary cowling member or shroud 191.Shroud 191 is attached to cabinet member 194 and defines an accessopening 195 aligned with an access opening 196 in cabinet member 1 94and covered by an access door 198. A heating element 199 is housedwithin shroud member 191 and is positioned for heating air entering theinterior of drum 189.

Positioned on the shroud 191 is at least one pair of electrodespositioned for contact by the tumbling fabrics.

These electrodes 200 and 201 may be connected to the sensing circuit bywires 202 and 203 for cooperating with the control circuit such asdescribed hereinabove in determining the electrical condition of thematerials being tumbled. These electrodes will of course be electricallyinsulated from cowling 191 by insulating members 204 placed between thecowling surface and the electrodes.

In the drawings and specification, there has been set forth a preferredembodiment of the invention and, althrough specific terms are employed,these are used in a generic and descriptive sense only, and not forpurposes of limitation. Changes in form and the proportion of parts, aswell as the substitution of equivalents are contemplated, ascircumstances may suggest or render expendient, without departing fromthe spirit or scope of this invention as further defined in thefollowing claims.

We claim:

1. In an apparatus for drying fabrics, the combination comprising:non-revoluble enclosure means; a revoluble drum at least partiallyenclosed by said enclosure means and including first and second end wallmembers, said first end wall member defining an opening into saidrevoluble drum; a non-revoluble panel member attached to said enclosuremeans and positioned in said opening openly facing the interior of saiddrum and positioned for effectively forming a non-revoluble extension ofsaid first revoluble end wall member; access means for allowinginsertion of fabrics into the interior of said revoluble drum; means forrotating said revoluble drum to tumble said fabrics therein; means fordrying said tumbled fabrics in said revoluble drum; at least one pair ofconductors associated with said non-revoluble panel member electri-callyinsulated from each other and positioned for contact by said tumbledfabrics to effect completion of an electrical circuit between said pairof conductors, said second end wall member being constructed anddisposed to direct said fabrics inwardly toward said pair of conductorsupon rotation of said revoluble drum; and control means connectedelectrically to said pair of conductors for terminating a dryingoperation responsive to a predetermined electrical condition betweensaid pair of conductors.

2. In an apparatus for drying fabrics, the combination comprising: arevoluble drum including an inwardly extending conical shaped first endwall member at one end thereof: a pivotally mounted nonrevoluble casingat least partially enclosing said drum and having a panel memberjuxtaposed to the other end of said revoluable drum, said panel memberhaving a generally annular portion positioned for effectively forming atleast a portion of a second end wall for said revoluble drum openlyfacing the interior thereof; access means for inserting fabrics into theinterior of said revoluble drum; means for rotating said revoluble drumto tumble said fabrics therein, said rotating means and said inwardlyextending conical shaped first end wall member being cooperative fortumbling said fabrics against said non-revoluble panel member; means fordrying said tumbled fabrics in said revoluble drum; at least one pair ofconductors associated with said non-revoluble panel member electricallyinsulated from each other and in a position for contact by said tumbledfabrics; and control means connected electrically to said conductors forterminating a drying operation responsive to a predetermined electricalcondition of said fabrics effecting completion of a circuit between saidconductors.

3. In an apparatus for drying fabrics, the combination comprising: arevoluble drum; a pivotally mounted nonrevoluble casing at leastpartially enclosing said drum and having a panel member juxtaposed toone end of said revoluble drum openly facing the interior thereof, saidpanel member being positioned for effectively forming at least a portionof an end wall for said revoluble drum; access means for insertingfabrics into the interior of said revoluble drum; means for rotatingsaid revoluble drum in a predetermined direction; means for drying saidfabrics in said revoluble drum; elevating means in said revoluble drum,said rota-ting means and said elevating means being cooperable formoving said fabrics from a lower region in said drum to an upper regiontherein from which said fabrics fall toward a predetermined lowerquadrant of said casing; at least one pair of conductors associated withsaid panel member, said conductors being positioned within saidpredetermined lower quadrant openly facing the interior of said drum forcontact by said tumbled fabrics; and control means connectedelectrically to said conductors for terminating a drying operationresponsive to a predetermined electrical condition between saidconductors.

References Cited by the Examiner UNITED STATES PATENTS 2,885,789 5/1959Conkling et al 34-45 2,985,966 5/1961 Martin 34l33 X 2,991,641 7/1961Woodling 3445 X FOREIGN PATENTS 877,553 9/1961 Great Britain.

FREDERICK L. MATT-ESON, JR., Primary Examiner.

WILLIAM F. ODEA, Examiner.

D. A. TAMBURR-O, Assistant Examiner.

1. IN AN APPARATUS FOR DRYING FABRICS, THE COMBINATION COMPRISING:NON-REVOLUBLE ENCLOSURE MEANS; A REVOLUBLE DRUM AT LEAST PARTIALLYENCLOSED BY SAID ENCLOSURE MEANS AND INCLUDING FIRST AND SECOND END WALLMEMBERS, SAID FIRST END WALL MEMBER DEFINING AN OPENING INTO SAIDREVOLUBLE DRUM; A NON-REVOLUBLE PANEL MEMBER ATTACHED TO SAID ENCLOSUREMEANS AND POSITIONED IN SAID OPENING OPENLY FACING THE INTERIOR OF SAIDDRUM AND POSITIONED FOR EFFECTIVELY FORMING A NON-REVOLUBLE EXTENSION OFSAID FIRST REVOLUBLE END WALL MEMBER; ACCESS MENS FOR ALLOWING INSERTIONOF FABRICS INTO THE INTERIOR OF SAID REVOLUBLE DRUM; MEANS FOR ROTATINGSAID REVOLUBLE DRUM TO TUMBLE SAID FABRICS THEREIN; MEANS FOR DRYINGSAID TUMBLED FABRICS IN SAID REVOLUBLE DRUM; AT LEAST ONE PAIR OFCONDUCTORS ASSOCIATED WITH SAID NON-REVOLUBLE PANEL MEMBER ELECTRICALLYINSULATED FROM EACH OTHER AND POSITIONED FOR CONTACT BY SAID TUMBLEDFABRICS TO EFFECT COMPLETION OF AN ELECTRICAL CIRCUIT BETWEEN SAID PAIROF CONDUCTORS, SAID SECOND END WALL MEMBER BEING CONSTRUCTED ANDDISPOSED TO DIRECT SAID FABRICS INWARDLY TOWARD SAID PAIR OF CONDUCTORSUPON ROTATION OF SAID REVOLUBLE DRUM; AND CONTROL MEANS CONNECTEDELECTRICALLY TO SAID PAIR OF CONDUCTORS FOR TERMINATING A DRYINGOPERATION RESPONSIVE TO A PREDETERMINED ELECTRICAL CONDITION BETWEENSAID PAIR OF CONDUCTORS.